Question

Find the area of triangle ABC if AB = BC = 12 and <ABC = 120 degrees

Should approach this with SSS similarity? If yes will the answer be clear or will i need to manipulate it, and how.

Answer 1

You can use the law of cosines to find side AC, then, use

area=sqrt(s(s-a)(s-b)(s-c))

where s is the half perimeter.

Answer 2

Have you come across this area formula for the area of a triangle ?
- if two sides are a and b, and Ø is the angle between them, then the area = (1/2)(ab)sinØ

so for yours,
area = (1/2)(12)(12)sin 120°
= .....